Clearance requirements in hydraulic piston rod packing rings
Axial clearance: It can ensure that the packing ring can float freely in the ring groove. If the gap is not suitable, it will affect its normal operation.
Radial clearance: mainly used to prevent the packing ring from being pressed when the piston rod sinks, resulting in deformation or damage.
Incision clearance: mainly used to compensate for the wear of the packing ring.
In automotive shock absorbers, the piston rod is a very important component, and its performance will affect the quality and service life of the shock absorber. And its performance is mainly depends on its corrosion resistance. And during the electroplating process, the electroplating process parameters will affect the quality of the coating and its corrosion resistance. Therefore, the piston rod is generally hard chrome plated to improve its corrosion resistance and wear resistance, so that it can meet the requirements of use.
Material selection of hydraulic piston rod
1. The piston rod is usually made of 45 steel. It is made of 40Cr steel with large impact force and heavy load transmission.
2. The piston rods are generally designed as cylinders. If the diameter is larger, the hollow piston rods can be used. Made of 45 seamless steel pipe.
3. When the piston rod is manufactured, the blank should be firstly subjected to forging and mechanical roughing and then quenched and tempered, and the hardness is HB=230-250. The purpose of quenching and tempering is to improve the machinability and increase the working strength of the material.
4. The surface roughness Ra of the piston rod after finishing should be no more than 0.65μm.
5. In order to improve the corrosion resistance of the piston rod, the working surface of the rod can be plated with hard chrome.
6. The piston rod and the guide sleeve on the end cover are matched with H8/f9. www.xhychromerod.com